A hall is $$25$$ m long. $$8$$m wide and $$5$$m high. Its walls and the roof are to be white wash inside. Find the total area to be washed(in $$m^2$$).
Area to be white washed $$=2(l+b)\times h +l\times b=2(25+8)\times 5 + (25\times 8) \\ =330+200=530m^2$$